It is common practice for fluid samples to be extracted from a pressurized pipeline for “on-line” analysis or laboratory analysis. Such is the case in the natural gas industry wherein the monetary value of the gas is dependent on its composition. The chemical and oil refining industries also have needs for extracting fluid samples from pressurized fluid sources.
Additionally sensors, such as pressure and temperature sensors and corrosion coupons often require insertion into pressurized fluid streams. There are many probe types designed to be inserted into pressurized fluid systems. There are pressure balance insertion methods, such as described in Mayeaux U.S. Pat. Nos. 7,472,615 and 6,701,794, which do not require forcing the probe through a seal. There are smooth walled probe types, such as described in Welker U.S. Pat. Nos. 6,964,517 and 6,827,486, which are forced through a seal into a pressurized fluid by pneumatic or hydraulic means. Another probe insertion method utilizes a threaded male membrane and threaded female nut to force a smooth walled probe through a seal into the pressurized fluid. An example is the Mudiam U.S. Pat. No. 5,106,580.
The aforementioned methods of probe insertion each have drawbacks. For example, the Mayeaux patents require a housing with foot valve which prevents it from being utilized in a horizontal position. The Welker patents describe probes requiring valving and pneumatic or hydraulic cylinders which complicates their construction and operation. The Mudiam patent describes a complex apparatus in which a rod type of probe is inserted by utilizing a separate threaded member.